Articulated motor grader



Sept 8, 1970 A. v. HAMPTON 3,527,315

AR'II CULATED MOTOR GRADER Filed May 9, 1968 2 Sheets-Sheet 1 mmmkgk .QWRWW 61). Z a "WW 22 W I M WpM/w Sept. 8, 1970 A. v. HAMPTON ARTICULATED MOTOR GRADER 2 Sheets-Sheet 2 Filed May 9. 1968 United States Patent 3,527,315 ARTICULATED MOTOR GRADER Andrew V. Hampton, Springfield, Ill., assignor to Allis- Chalmers Manufacturing Company, Milwaukee, Wis. Filed May 9, 1968, Ser. No. 727,983 Int. Cl. B60k 17/30 U.S. Cl. 180-51 2 Claims ABSTRACT OF THE DISCLOSURE A motor grader having a rear two-wheel tractor unit is articulately connected to the rear end of a tool frame, and the front end of the tool frame is articulately connected to a front wheel drive unit. The front wheel drive unit includes an oscillating axle assembly with a pair of leanable drive wheels. The front wheel unit incorporates the features of articulated or wagon steer relative to the tool frame, oscillation of the axle thereof about a longitudinal axis, power driven wheels which are leanable.

This invention relates to a motor grader having a front wheel drive unit which is articulatively connected to the tool frame for pivotable movement about a vertical axis and has an oscillating axle assembly with wheels which may be laterally leaned.

Heretofore, motor graders of various types have been developed and marketed, some of the prior rnotor graders have employed double articulation steering and some have employed powered front wheels. While these prior motor graders have enjoyed some measure of success, there still existed a need for improved performance and capabilities. The present invention provides a double articulated motor grader having a wagon steer type front unit with wheels that are leanable and power driven. Motor graders employing the present invention have improved maneuverability and work capability, particularly when used in ditching and bank slope operations.

It is an object of the present invention to provide an improved motor grader having double articulation steering.

It is a further object of this invention to provide an articulated front wheel unit for a motor grader which has front axle oscillation and power driven wheels which may be leaned.

It is a further object of the present invention to provide an improved motor grader having a rear two-wheel power unit which is substantially interchangeable with the rear power unit of an articulated loader.

It is a further object of this invention to provide an improved articulated motor grader of the type hereinbefore outlined which is relatively low in initial, cost, has a high horsepower-to-weight ratio, and has improved working capability.

These and other objects of this invention will be apparent to those familiar with the art when the following description is read in conjunction with the drawings in which:

FIG. 1 is a side view of the motor grader incorporating the present invention;

FIG. 2 is a vertical section through the front articulation joint of the motor grader;

FIG. 3 is a top view of the motor grader shown in FIG. 1; and

FIG. 4 is an enlarged front view of the motor grader with parts thereof shown in section.

Referring to FIG. 1, the motor grader 11 is made up of three major components; namely, a rear power unit 12, an elongated tool supporting frame 13, and a front drive unit 14. The rear power unit 12 is essentially the twowheel power unit of an articulated tractor loader and,

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as illustrated, such unit has an internal combustion engine 15 providing power to the rear wheels 14 through a change speed transmission 16. The rear unit 12 also includes an operators station 17 at which steering controls, in the form of a steering wheel 18, are located. The longitudinally extending tool supporting frame 13 has its rear end articulately connected to the front of the rear unit by a pair of vertically spaced aligned pivot pins 21, 22.

As shown in FIG. 3, the tool supporting frame 13 and rear unit 12 are steered relative to one another about the vertical articulation axis 23 by a pair of doubleacting hydraulic jacks 24, 26 which have their cylinder ends pivotally connected to the rear unit 12 and their piston rods pivotally connected to the tool supporting frame 13. The front unit includes a hitch frame 31 which is pivotally connected to the front end of the tool supporting frame by a pivot pin 32 and an antifriction bearing 34. As shown in FIGS. 2 and 4, the front unit also includes an axle assembly 36 which has a cradle 35 with front and rear plates 44, 45 pivotally connected to the hitch member 31 on a longitudinal axis 37 by a pair of aligned pivot pins 38, 39. This permits oscillation of the axle assembly 36 about axis 37 within the limits imposed by abutments 86, 87 on the cradle 35 and abutments 88, 89 on plate of the intermediate hitch member 31. The vertical end plates 92, 93 of cradle 35 are sandwiched between the central axle housing portion 94 and housing extensions 57, 58, such components being held in assembly by fastening means such as cap screws, not shown. The input shaft 41 of the axle assembly 36 is connected in driven relation to an output shaft 42 of the transmission 16 by a power train 43 which extends through the hollow interior of frame 13. The axis of the input shaft 41 coincides with the vertical articulation axis 46. The front wheel unit 14 is steered relative to the tool supporting frame 13 about axis 46 by a pair of double-acting hydraulic jacks 47 and 48 which have their cylinders trunnion mounted on the tool supporting frame and their piston rods pivotally connected to the intermediate hitch member 31. The controls for the steering jacks 47, 48 include a hydraulic control valve, not shown, which is operatively connected to steering wheel 18.

A pair of wheel spindles 53, 54 are pivotally connected to axle housing extensions 57, 58 of assembly 36 for front wheel lean movement about longitudinal axes 61, 62. Front drive wheels 51, 52 are rotatably mounted on spindles 53, 54, respectively, and are connected in driven relation to input shaft 41 of the axle assembly 36 through a differential 56. As shown in FIG. 4, the drive to the front wheel 52 includes a jack shaft 96 and planetary gear set 97. A tie rod 63 is pivotally connected at its opposite ends to wheel spindles 53, 54 by pins 59, 60, and the lateral leaning of the wheels 51, 52 about axes 61, 62 is accomplished by power means in the form of hydraulic jacks 64, 66. As seen in FIGS. 2 and 3, the tie rod 63 includes an intermediate portion which lies between the pins 38, 39 and which is curved slightly to the rear to avoid interference with vertical input shaft 41. The hydraulic jacks 64, 66 have their cylinders pivotally connected to braces 67, 68 of cradle 35, and their piston rods pivotally connected to pivot pins 59, 60.

The tool supporting frame 13 has a draft member in the form of a socket 71 near its forward end to which a complementary hitch part, in the form of a ball member 72 of a drawbar and circle assembly 73, is connected. The earthworking blade 74 of the motor grader is mounted on the circle assembly 73 in a conventional manner for swinging adjustment about a vertical axis by a hydraulically powered drive unit 76. The blade 74 and circle assembly 73 are adjusted vertically by a pair of doubleacting hydraulic jacks 81, 82 which have their cylinders trunnion mounted to the tool supporting frame 13 and their piston rods pivotally connected to laterally spaced points on the circle assembly 13.

As shown in FIG. 3, the double articulated motor grader of the present invention may be articulately steered to the position shown in phantom lines 91. This position of the motor grader frame and front wheel unit is particularly useful in working in ditches and on banks or slopes. For instance, in cleaning up ditches, the rear power unit can remain on the shoulder of the road while the front wheels run in the ditch; or in working a slope, the front wheels can ride on the bank of a slope while the rear wheels travel at the base of the slope. When doing extended reach work, the rear wheels can be offset from the front wheels to provide good blade position without discharging dirt beneath the rear driving wheels.

It has also been found that the improved maneuverability of a motor grader using this invention permits snowplow operations to be accomplished more effectively with a higher degree of safety, particularly in mountainous terrain. The power unit need not travel close to the edge of the road during such snow plowing operations. The improved maneuverability of motor graders using the present invention makes such motor graders a markedly more versatile machine on a wide variety of earthmoving and grading projects. The articulated grader of the present invention does superior finishing work around culverts, driveways, buildings and other structures where maneuverability is an important factor in productivity. It has been found that a higher horsepower per unit weight ratio can be utilized in a machine incorporating the present invention; thus, increasing its work capability. Also, it has been found that effective performance is obtainable without the use of ta dem rear wheels, although tandem rear wheels could be used if desired. By locating the operators station 17 on the front of the tractor unit 12 in overlying relation to the vertical pivot axis 23, the operator is not only positioned where he has a good view of the Working tool or blade 74, but also will have a definite feel of the steered condition of the tractor unit 12 relative to the frame 13.

Although only one embodiment of the present invention has been illustrated and described, other embodiments may be envisioned by those familiar with the art without departing from the spirit of the invention.

The embodiments of the invention for which an exclusive property or privilege is claimed are defined as follows:

1. A double articulated earth-working machine comprising:

a tractor unit having ground engaging traction means and a source of power connected to said traction means,

a longitudinally extending tool supporting frame pivotally connected at its rear end to said tractor unit for steering movement about a vertical pivot axis, and

4 a front unit including a hitch member pivotally connected to the front end of said frame on a vertical steer axis and pivotable on said steer axis independently of pivotal movement of said frame about said vertical pivot axis, an axle assembly pivotally connected to said hitch member for oscillating movement about a longitudinal axis by a pair of longitudinally spaced pivot elements and wheel spindles pivotally connected, respectively, to transversely opposite ends of said axle assembly for lateral leaning movement about longitudinal tilt axes, drive wheels rotatably mounted on said spindles,

respectively, and an input shaft in said axle assembly mounted for rotation on said steer axis and connected to said drive wheels, tilt means operable to adjust said spindles relative to said axle assembly about said tilt axes including a transverse tie rod pivotally connected at its opposite ends to said spindles, respectively, at points thereon above said tilt axes and having an intermediate portion disposed between said pivot elements, power transmitting means interconnecting said source of power and said input shaft, and first and second steering jacks connecting said tractor unit and hitch member, respectively, with said frame for selective steering movement relative to the latter. 2. The invention of claim 1 and further comprising upper and lower pivot means pivotally interconnecting said hitch member and frame, said lower pivot means including a bearing encompassing the part of said power transmitting means connected to said input shaft.

References Cited UNITED STATES PATENTS 641,834 1/1900 Bullard -42 1,055,010 3/1913 Zager. 1,079,607 11/1913 Schieler 180-42 1,405,159 l/l922 Polaski et al. 180-42 2,130,274 9/1938 Harrison et al. 172-798 X 2,195,607 4/1940 Wilson et a1 172-799 X 2,494,324 1/ 1950 Wright 172-793 2,625,231 l/1953 Martin 180-49 2,748,509 6/1956 Brown et al. 172-799 3,431,741 3/1969 Kinnan 172-781 ROBERT E. PULFREY, Primary Examiner A. E. KOPECKI, Assistant Examiner US. Cl. X.R. 

